To be blunt, I have yet to see any wide angle rectilinear lens that gives acceptable corners at f/8 on Nikon Full Frame cameras. I'm pretty sure that no one has!
My experience, both in controlled tests and in actual use is that the 16-35mm outperforms the 14-24 at all apertures.
The issue here is not optical quality, but is the lens's ability to focus close and maintain sufficient DOF to keep the corners in focus. No current lens manufacture prioritizes close focus ability with wide angle lenses as they are not normally used this way. For one lens to do so better is just happy circumstance, rather than design.
Still as you say, if it doesn't work you can use it on land
Or you could save the money, get the 16-35mm and go on a holiday and take some amazing pictures!
Adam